Ammunition



April 30,1946. w, SMITH 2,399,398

AMMUN IT ION Patented Apr. 30, 1946 UNITED STATES ATENT OFFHCEApplication August 4, 1941, Serial No. 405,449 In Great Britain July 5,1940 2 Claims.

This invention relates to guns and especially to the charge by which ashell (which term is intended to include all projectiles fired fromguns) is fired from a gun.

In accordance with the invention, an explosive charge is enclosed in acasing which in use, fits within the breech of the gun and is held,during the initial expansion after the charge is fired, to provide a gascheck and secure substantially com; 'plete combustion of the chargebefore the shell is moved.

The casing (or the forward part thereof) is expanded, when the charge isfired, into close contact with the breech of the gun and forms anobturator ring behind which the charge ex: pands.

One advantage of the improved charging device is that, since anobturator ring is formed by the casing, the shell need not be an exactfit in the bore of the gun which is especially advantageous when the gunis not rifled.

In the accompanying drawing which illustrates three preferredembodiments of the invention,

Figs. 1 and 2 represent in section and end view respectively a chargecasing for a breech loading gun,

Fig. 3 shows a section through a similar casing for a breech loading gunemploying finned shells,

Fig. 4 shows in section a charge casing suitable for a nozzle loadinggun,

Fig. 5 shows a modified detail.

In the form shown in Figs. 1 and 2 the charge casing comprises adish-shaped member A having a cylindrical wall B of such diameter as tofit fairly closely within the breech of the gun. This cylindrical wallis turned outwardly to provide an annular flange C.

Projecting centrally from the base of this dishshaped member is acylindrical tube D. This central tube is intended to receive primingmaterial (for instance, gunpowder) being retained by a paper disc E- Theexplosive charge, for example cordite, surrounds the tube and is held bya prepared paper container F.

The casing is closed by a back plate G which around its edge is turnedover the annular flange C of the front part of the casing, for instanceby spinning or stamping, locking the container F in position. This platehas a central aperture for the reception of a detonator H which isturned over a washer J. A removable protection disc K prevents damp fromentering the casing and facilitates safe handling.

The charge case is connected to the projectile proper by a screwedsleeve L which engages a screwed spindle M which passes through themember L and has a flange N and a sealing P for the tube D. The breechcap is then closed and the flange C on the charge casing is held firmlybetween the breech cap and the end of the gun.

When the firing pin is operated the detonator H is caused to ignite thepriming material in the tube D which in turn ignites theexplosive'charge. As the explosive charge is completely enclosed, theinitial expansion will take place only within the casing so that theexpansion is checked until the pressure within the casing is suflicientto disrupt the joint between the two parts of the casing and to draw theforward part thereof out of the grip between the breech cap and the gun.

The forward part ofthe casing is then driven forward by the pressuregenerated by the gases and drives the shell forward out of the gun.

During the period when the casing is held, the internal pressure due tothe combustion of the charge expands the cylindrical wall of the casingagainst the bore of the gun so that the front part of the casing whenreleased forms an obturator ring behind which the gases expand. It willbe seen that as the shell itself need be only a very slack fit in thegun bore, the resistance to the forward movement of the shell is verysmall.

Furthermore, after the casing is disrupted, the gases tend to expand thechannelled edge of the back disc forcing the walls thereof into contactwith the breech cap and the end of the gun barrel, thereby providing aneffective seal at this position.

The check to the expansion of the gases ensures substantially completecombustion of the charge before the expansion occurs thereby increasingthe expansive force eventually exerted to fire the shell. The inventionthus provides a gas check for unrifled guns having an efiect similar tothat provided during the initial combustion of the charge by the rifiingin rifled guns.

The charge casing may be of any suitable material though it is preferredto use brass or steel plate.

The forward part of the casing passes from the barrel with the shell andthe back plate drops out when the breech cap is opened.

Referring now to the construction shown in Fig. 3 the case is verysimilar to that already described but the member A is shaped to engage adished impact disc Q which is held in position by an impact spindle Rscrewed on to the spindle M.

Surrounding the impact spindle R is an impact tube S fitted inside thefar end of the shell Z.

The charge case is pushed into the open end of the shell and is lockedin position by a detent W carried on a spring link V secured by a screwY to the impact spindle R.

The detent W engages one of the holes U between the fins T and ispreferably loaded by a weight W.

In the form shown in Fig. 4 the charge casing comprises a dish-shapedmember a having a cylindrical wall I) of such diameter as to fit fairlyclosely within the breech of the gun.

Projecting centrally from the base of this dishshaped member is acylindrical boss c having a number of apertures d in its wall. Thiscentral boss is intended to receive a firing detonator e or firingcartridge which is inserted in a sleeve 9 screwed into the boss.

Priming material (for instance, gunpowder) is placed around the outsideof this tube, being preferably enclosed in a sheath of paper forexample, to keep it in position. The explosive charge, for examplecordite, surrounds the priming material and may fill the space betweenthe priming material and the cylindrical wall of the casing.

A flanged closure member I, issecured to the inner surface of the fiangeb of the dish-shaped member and fits over the central boss and issecured in position by a hollow sleeve g engaging an internal thread onthe boss, an appropriate number of washers h, ;i being interposed; thesewashers may be in laminations, starred on edges, or they may haveconical corrugations.

The boss hasa projecting portion k of reduced diameter which passesthrough a hole in the base of the dished shaped member which is securedto the shoulder of the boss by a nut i or similar device. Thisprojecting portion is is screwed into the shell proper,

The pressure of the gases causes the closure member 1 to bend back afterbreaking the joint with the wall b to a position indicated by dottedlines so that the member I passes out of the gun with the shell.

Referring now to Fig. .5 this shows a modified detail of theconstruction shown in Fig. 1. The screwed sleeve L and screwed spindle Mare replaced by a screwed member I which has a projecting portion pwhich passes through the dishshaped member A and container F and isturned over a ring 72. On this ring fits a tube 111, for primingmaterial provided with six holes q which are closed by a paper or likeenvelope until the detonator is fired.

The invention is not restricted to the details above described butincludes all constructions and modifications coming within the ambit ofthe claims which follow.

I claim: I v I .1. A closed cylinder charge box for a projectile to beinserted into the breech of a gun, said box including a dish-shaped bodyhaving a cylindrical wall of a diameter slightly less than the diameterof the gun bore, an end plate, a separable end joint connecting the saidwall and end plate and arranged wholly beyond the plane of thecylindrical wall, a priming material tube arranged centrally of thecylindrical wall and terminating shortof the end plate, a detonatorcarried solely by the end plate, and an explosivecharge carrier in thebox and surrounding the tube the explosive charge carrier beingdestructible under the ignition of the explosive charge, said explosivecharge carrier being arranged concentric with the priming material tubeand of gradually increasing diameter towards the end plate.

2. A closed cylinder charge box for a projectile to be inserted into thebreech of a gun, said box including a dish-shaped body having acylindrical wall of a diameter slightly less than the di ameter of thegun bore, an end plate, a separable end joint connecting the said walland end plate and arranged wholly beyond the plane of the Cylindricalwall, a priming material tube arranged centrally of the cylindrical walland terminating short of the end plate, a detonator carried solely bythe end plate, and an explosivech-arge carrier in the box andsurrounding the tube, the explosive charge carrier being destructibleunder the ignition of the explosive charge, said explosive chargecarrier being arranged concentric with the priming material tube and ofgradually increasing diameter towards the end plate, and of the fulldiameter of the cylindrical wall adjacent the end plate.

WILLIAM HERBERT SMITH.

